/**
 *
 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either 
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public 
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 * 
 **/
package lucee.commons.lock;

import lucee.runtime.exp.PageException;

public interface Lock {

	public void lock(long timeout) throws PageException;

	public void unlock();

	/**
	 * Returns an estimate of the number of threads waiting to acquire this lock. The value is only an
	 * estimate because the number of threads may change dynamically while this method traverses
	 * internal data structures. This method is designed for use in monitoring of the system state, not
	 * for synchronization control.
	 * 
	 * @return the estimated number of threads waiting for this lock
	 */
	public int getQueueLength();
}